Directions: Read the passage carefully and answer the questions that follow.
The lobia (black-eyed pea) seeds that the Indian Space Research Organisation (ISRO) sent to space on December 30 as a part of its Compact Research Module for Orbital Plant Studies (CROPS) germinated last week.
Why grow plants in space?
As humans venture out on lengthy space missions to colonise celestial bodies like Mars and the Moon, space-grown plants can provide a sustainable food source. With minimal scope of restocking supplies, astronauts cannot simply rely on a limited stock of multivitamins during missions that may go on for years. Besides, pre-packaged vitamins break down and lose their nutritive value over long periods of time.
Since plants release oxygen during photosynthesis, growing them in space can help keep the air aboard spacecraft breathable, Siddharth Pandey, an affiliate research scientist with US-based Blue Marble Space Institute of Science, told The Indian Express. “Plants can recycle carbon dioxide and organic waste, creating a closed-loop life support system,” Pandey said.
Tending to plants can also help reduce stress and improve astronauts’ overall mental well-being, he said.
Why is it hard to grow plants in space?
The most significant challenge is microgravity, the condition in which people or objects appear to be weightless.
The lack of gravity precludes plants’ roots from growing downwards, in addition to making nutrient delivery a difficult task. Since water tends to cling to any surface it touches in microgravity, when sprayed onto the base of a plant, it does not trickle down to the roots where it would be absorbed.
Plants grown in space also need to be protected from the high levels of radiation that can damage their DNA and hinder growth, and insulated from temperature fluctuations — often hundreds of degrees — that are normal in space, Pandey said.
Light conditions, especially in the outer Solar System where sunlight is scarce, pose another challenge. Without light, photosynthesis stops, and plants begin to consume more oxygen than they produce.
How are plants being grown in space?
Scientists have so far grown plants in space on a fairly small scale. The space garden aboard the International Space Station, known as ‘Veggie’ or the Vegetable Production System, is the size of the average carry-on bag. It typically holds six plants.
There are several ways in which plants can be grown in space. The most common is hydroponics, Pushkar Ganesh Vaidya, head of the Indian Astrobiology Research Foundation, said. Water and nutrients in hydroponically grown plants are delivered via liquid solutions, rather than through the soil.
Plants can also be grown aeroponically, which eliminates the need for soil or any other medium. This method reduces water usage by 98%, fertiliser usage by 60%, and eliminates the need for pesticides altogether. “Plants grown in aeroponic systems have been shown to absorb more minerals and vitamins, making them healthier and potentially more nutritious,” according to the US space agency NASA.
Plants can also be grown in space in soil-like media.
How did ISRO grow lobia in space?
“The ISRO CROPS box is like a mini greenhouse,” Vaidya said. It has a soil-like medium, lobia, water, sunlight-mimicking lights, and Earth-like air. “The only thing different is gravity, at around 0.01 g”, or 1% of the gravitational strength on the Earth’s surface, he said.
For the soil-like medium, ISRO used some highly porous clay comprising tiny pellets. The porosity helped absorb and retain water. The pellets consisted of a water-activated slow-release fertiliser, which was to provide nutrients to the plant in a controlled manner over a period of time.
For photosynthesis, ISRO used four warm LEDs and four cool LEDs. “The lights are programmed to be on for 16 hours and off for 8 hours, simulating day and night conditions… These durations can be changed based on various requirements,” ISRO said in a statement.
Temperatures inside the module were regulated between 20 and 30 degrees Celsius, and Earth-like atmospheric conditions were maintained. Water was injected into the soil-like medium by an electric valve operated from Earth.
Seeds sprouted on the fourth day of the experiment, and the next day, two leaves were also visible.
What kind of plants are ideal for growing in space?
Plants are selected based on their growth rate, nutrient content, and compatibility with space farming systems, Pandey said.
Leafy green vegetables like lettuce, spinach, and kale, which grow quickly, require little space, and are rich in nutrients, are ideal space plants.
Beans and peas are also cultivated since they are protein-dense and can fix nitrogen in the soil-like medium, improving nutrient cycles.
“Radishes and carrots grow well in compact spaces… Wheat and rice are grown for long-term sustenance in space habitats,” Pandey said. Fruits such as tomatoes and strawberries can also be grown.
[Excerpt from TOI "ISRO Successfully Germinates Black-eyed Pea Seeds in Space" Dated 18/01/25]
Q1: What is the primary goal of ISRO’s CROPS project?
(a) To develop new spacecraft designs
(b) To explore plant growth in space
(c) To mine resources on celestial bodies
(d) To simulate microgravity environments on Earth
Ans: (b)
Sol: The primary goal of the CROPS project is to explore plant growth in space.
Q2: What was the significant achievement of CROPS-1?
(a) Development of artificial soil
(b) Demonstration of seed germination and initial plant growth in space
(c) Collection of water samples from space
(d) Design of a new irrigation system
Ans: (b)
Sol: CROPS-1 demonstrated seed germination and initial plant growth in a controlled environment aboard a spacecraft.
Q3: What challenge does microgravity pose for plant growth in space?
(a) Excessive soil density
(b) Inadequate sunlight exposure
(c) Roots cannot grow downwards, and water distribution becomes difficult
(d) Lack of photosynthesis
Ans: (c)
Sol: In microgravity, roots cannot grow downwards, and water distribution is challenging, which makes plant growth difficult.
Q4: Which method involves using mist to deliver nutrients to plants in space?
(a) Hydroponics
(b) Aeroponics
(c) Soil-based cultivation
(d) Cryoponics
Ans: (b)
Sol: Aeroponics uses mist to deliver nutrients, reducing water and fertiliser usage.
Q5: What type of medium was used in CROPS-1 for germination?
(a) Hydroponic solution
(b) Porous clay pellets
(c) Regular soil
(d) Rock wool
Ans: (b)
Sol: CROPS-1 used a soil-like medium made of porous clay pellets for germination.
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